Let’s break this down.
You start with the video macro prefix, video::.
Next is the target.
Put the path of the video relative to the video catalog in that slot (no need for an attribute prefix).
Finally, end with a pair of square brackets ([]).

Add a YouTube or Vimeo video

To embed a video hosted on YouTube or Vimeo, put the video’s ID in the macro target and the name of the hosting service (youtube, vimeo) between the brackets.